The Fixation oe Nitrogen. 
25 
ANALYSES 
XXVII 
XXVIII 
Water-Soluble 
Water-Soluble 
laboratory 
laboratory 
No. 877 
No. 778 
Surface Soil 
Sample taken 
8 inches deep 
top 2 inches, 
removed 
April, 1909 
Percent 
Percent 
Calcic sulfate .... 
38-643 
Calcic chlorid . . . 
. 3.521 
Magnesic chlorid 
Magnesic sulfate . 
. 14.611 
11.082 
Potassic chlorid . 
. 2.215 
Potassic sulfate . . 
9.500 
Sodic sulfate .... 
2.473 
Sodic chlorid .... 
. 51.474 
33.854 
Sodic nitrate .... 
. 12.596 
3.784 
Iron and Aluminic 
oxid. 
. Trace 
0.100 
Manganic oxid . . . 
. 0.094 
0.042 
Silicic acid . 
. 0.144 
0.522 
100.000 
100.000 
In this case we find in April, 1909, that the top two inches 
of this soil showed the presence of one and a half tons of sodic 
nitrate. Another sample taken in November of the same year, 
and perhaps one hundred and fifty feet north of where the sample 
was taken in April, gives us essentially the same amount, one and 
a half tons in the top two inches. But the same depth of soil taken 
November 2, the same year and very nearly at the same point 
where the April -sample had been taken, showed the presence of 
almost four tons, 3.978 tons, of nitrate in the top two inches per 
acre. A sample of this soil taken from the third to the tenth inch 
inclusive in April, 1909, or eight inches of the soil, after the top 
two inches had been removed, showed the presence of 2,306 pounds, 
a little over one ton to the acre taken to this depth, eight inches. 
This land had been excessively irrigated ten or twelve times during 
the season of 1908 with the idea of washing out the alkali. There 
were no signs of trouble in this land prior to 1904 according to 
the statement of its former owner. 
Sample No. 875 was taken from ground which had been used 
as a truck garden in 1908. I scarcely need to state that the truck 
garden was a failure. This young orchard, Case No. 8, is used for 
the same purpose, i. e., gardening, and with excellent results except 
in this brown area. Analyses XV to XXVII inclusive are analyses 
of the alkali, the soil, and the ground waters which lie to the north 
and east of this land, not quite surrounding it but including the 
land through which the ground waters would have to move in 
order to reach this orchard. These samples were taken in 1907 
and contained no nitrates—or only such traces as may be found 
by extracting any soil. I may state, though it is very evident, 
that neither Bulletin 155 nor this one deals at all with such quan- 
